In a multiple input multiple output (MIMO) wireless communication system, a diversity gain or a multiplexing gain is obtained by arranging a plurality of antennas having the same characteristic at an interval which is equal to or more than half a wavelength of a carrier frequency. The reason for arranging the plurality of antennas at an interval which is equal to or more half the wavelength is that the diversity gain or the multiplexing gain is decreased since channel characteristics become similar due to pattern similarity between the antennas by the plurality of antennas having the same characteristic being arranged at an interval which is within half the wavelength.
In MIMO technology, the number of antennas is not great, such as 2×2, 4×4, 8×8, etc., but in massive MIMO technology, which is next generation communication technology, the number of antennas is remarkably increased, such as 32, 64, 128, etc. In this case, a space occupied by the antennas may be a problem due to using a plurality of antennas. For this, using antennas utilizing a pattern/polarization characteristic has been proposed.
Since a radiation pattern characteristic of an antenna shows a difference according to a structure of the antenna, an antenna utilizing the pattern/polarization characteristic can increase an integration rate per unit of space when compared to a conventional antenna. Further, a characteristic in which a channel gain is isolated due to an intrinsic characteristic of an antenna using the pattern/polarization characteristic has been shown.
In a conventional coordinated multi-point (CoMP) transmission and reception system, base station coordination methods such as micro diversity, coordinated silence, coordinated beamforming, etc. have been proposed, and such base station coordination methods consider an environment in which a beam is not introduced, or do not consider a case of using antennas using the pattern/polarization characteristic even when considering a beam.
A base station coordination method is needed in a beam division multiple access environment using antennas using the pattern/polarization characteristic.